Quasi-Elliptic Microstrip Low-Pass Filters Using an Interdigital DGS Slot

This letter introduces a DGS slot with an interdigital shape. The resonant frequency of the slot can be easily controlled by changing the length of the metal fingers, without changing the area taken by the structure. Using this slot, two quasi-elliptic low-pass filters were designed, fabricated and tested. The filters have a cut-off frequency of about 3 GHz.

[1]  A. Boutejdar,et al.  Compact stub type microstrip bandpass filter using defected ground plane , 2004, IEEE Microwave and Wireless Components Letters.

[2]  Jr. R. Wyndrum.  Microwave filters, impedance-matching networks, and coupling structures , 1965 .

[3]  A. Abdel-Rahman,et al.  Control of bandstop response of Hi-Lo microstrip low-pass filter using slot in ground plane , 2004, IEEE Transactions on Microwave Theory and Techniques.

[4]  Dal Ahn,et al.  A design of the novel coupled line bandpass filter using defected ground structure , 2000, 2000 IEEE MTT-S International Microwave Symposium Digest (Cat. No.00CH37017).

[5]  Jong-Sik Lim,et al.  A design of a miniaturized 2-pole bandpass filter by using a slot and a hair-pin line , 2004, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535).

[6]  Jun-Fa Mao,et al.  An improved 1D periodic defected ground structure for microstrip line , 2004 .

[7]  Y. Qian,et al.  A design of the low-pass filter using the novel microstrip defected ground structure , 2001 .

[8]  Sio-Weng Ting,et al.  Compact Microstrip Quasi-Elliptic Bandpass Filter Using Open-Loop Dumbbell Shaped Defected Ground Structure , 2006, 2006 IEEE MTT-S International Microwave Symposium Digest.

[9]  E. M. Jones,et al.  Microwave Filters, Impedance-Matching Networks, and Coupling Structures , 1980 .

[10]  Mi Yuan-ge.  Compact Stub Type Microstrip Bandpass Filter Using Defected Ground Plane , 2008 .

[11]  A.R. Ali,et al.  Direct and cross-coupled resonator filters using defected ground structure (DGS) resonators , 2005, 2005 European Microwave Conference.

[12]  Ke Wu,et al.  Unified CAD model of microstrip line with backside aperture for multilayer integrated circuit , 2000, 2000 IEEE MTT-S International Microwave Symposium Digest (Cat. No.00CH37017).